The present invention relates to a spray device for an inkjet printer and a spraying method thereof. More particularly, the invention relates to a spray device of an inkjet printer and its spraying method, capable of preventing energy leakage by structuring a predetermined area which does not wet with an ink in a nozzle plate of a common electrode as an insulating layer, in a spray device for performing printing by applying a low voltage between two electrodes from different layers, generating bubbles in an ink chamber with Joule heat from the conductive ink and spraying the ink to opening with a vapor pressure.
The use of conductive ink heated between two electrodes and the use of a narrow opening in the nozzle plate for expelling ink onto the print media is demonstrated in U.S. Pat. No. 5,400,061 for an Ink-Jet Printer Head to Horio et al. The ink is heated inside a chamber between two electrodes of opposite polarity and is expelled through a relatively narrow discharge hole in the nozzle plate of the device. However, the two electrodes are kept away from the nozzle plate, and are both located on a base plate underneath the conductive ink chamber. I have not seen an ink spray nozzle where one of the two electrodes is located on the nozzle plate or about the discharge hole of the chambered device.
Accordingly, the present invention is directed to a spray device of an inkjet printer and its spraying method that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object to provide a spray device for an inkjet printer where a surface of a nozzle plate used for a common electrode is equally coated as an insulating layer, and an inner side, namely, a side of an ink chamber is made of a conductor, so that the spray device has a simple structure, an easy fabrication, and prevents the loss of power.
Another object is to provide a spray device of an inkjet printer and its method thereof, preventing the centering of the current density and the loss of power caused therefrom, so that alow voltage operation and a uniformity in positions of the generated bubbles are settled and thus the drops are straightly printed.
Another object is to provide a spray device of an inkjet printer and its spraying method, increasing a current density around the firstly generated bubble, successively forming bubbles around the area and deforming them to thereby increase the entire vapor pressure.
Still another object is to provide a spray device for an inkjet printer and its spraying method, coating a predetermined opening of a nozzle plate with a conductive layer to stabilize a flow of a current density generated in a conductive ink by electrical energy applied to two electrodes in a chamber of the ink spray device, thereby enhancing the quality of printing.
Yet another object is to provide a spray device for an inkjet printer an its spraying method, structuring a nozzle plate into multiple layers by forming surface wetted with an ink in an ink chamber in a nozzle plate as a conductive layer made of Ni or Platinum alloy, and also forming the other surface facing media as an insulating layer, to thereby center the energy generated through the conductive ink, and prevent the power leakage.
Still another object is to provide one of the two electrodes that electrify the conductive ink in the discharge hole of the nozzle plate of the spray device.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other objects, the invention has a prominent characteristic that bubbles are formed by heat generated according to a flow of an internal current density in the conductive ink in the ink chamber, not in the surface of electrode.
Another characteristic of the invention is that the nozzle plate is used for a common electrode and thus its surface is coated for the conductive layer.
Far another characteristic of the invention is that there is used the conductive ink containing a predetermined resistant substances.
Still another characteristic of the invention is that the nozzle plate is electrically separated from the individual electrode, formed on the different layers, and thus used for the common electrode to thereby generate bubbles in the ink, the surface wetting with the ink is formed as the conductive layer, and the other surface facing to media is formed as the insulating layer.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.